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Fixed links.

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Dale Floer 2022-01-03 20:06:57 -08:00
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docs/hardware/antenna/non-aerial.md
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@ -16,9 +16,9 @@ Unless you're using your devices in a vacuum with clear line of sight between ae
### Environmental factors
For a bit of light reading on environmental research:
- [RF attenuation in vegetation](https://www.itu.int/dms_pubrec/itu-r/rec/p/R-REC-P.833-9-201609-I!!PDF-E.pdf) (yes really); if you wander through the woods wondering how your RF is bouncing off leaves dependent on their variety, and wind speed … well you do, now.
- [RF attenuation in vegetation](https://web.archive.org/web/20201216041455/https://www.itu.int/dms_pubrec/itu-r/rec/p/R-REC-P.833-9-201609-I!!PDF-E.pdf) (yes really); if you wander through the woods wondering how your RF is bouncing off leaves dependent on their variety, and wind speed … well you do, now.
- [RF attenuation with various building materials](https://www.ofcom.org.uk/__data/assets/pdf_file/0016/84022/building_materials_and_propagation.pdf).
- This one by ITU again is very detailed in its [analysis of the drivers of attenuation](https://www.itu.int/dms_pubrec/itu-r/rec/p/R-REC-P.2040-1-201507-I!!PDF-E.pdf) (I wasn’t aware that all EMF radiation exhibits reflection / transmission characteristics akin to light hitting a material boundary. So, depending on the angle of incidence, material and the EMF wavelength, it will be reflected and / or transmitted through).
- This one by ITU again is very detailed in its [analysis of the drivers of attenuation](https://web.archive.org/web/20211005174833/https://www.itu.int/dms_pubrec/itu-r/rec/p/R-REC-P.2040-1-201507-I!!PDF-E.pdf) (I wasn’t aware that all EMF radiation exhibits reflection / transmission characteristics akin to light hitting a material boundary. So, depending on the angle of incidence, material and the EMF wavelength, it will be reflected and / or transmitted through).
- These RF bands are also made more [noisy by adjacent LTE](https://www.ofcom.org.uk/__data/assets/pdf_file/0023/55922/lte-coexistence.pdf)
In summary - wavelengths in Europe fair well in plain sight, curve over not-so-tall obstacles (including trees), reflect of surfaces at low angles of incidence. They go through humans without much attenuation; but not brick or stone or anything much above glass / Kevlar. Oh, and don’t sit under an LTE tower and expect it to be plain sailing.